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Demystifying Keto, Part 1


*It is worth noting here that I am referring to carbs consumed in your daily diet, not while exercising. That is beyond the scope of this article and will be addressed in subsequent issues of Endurance News. However, I will give you a hint: I use Perpetuem® and Hammer Gel® for my OCR fueling needs!

Now more than ever, sapiens are showing their amazing innate ability to be divisive: good or bad; right or left; true or false; fad diet or wonderful, ancient, panacea for performance-enhancing, adipose-shedding yummy, fatty bits of enlightenment. Like most things diet, there are heaps of misinformation, dogma, and emotion about ketogenic eating. My goal is to help you understand a little more about what’s going on here.

Full disclosure: I have never recommended that patients eat a KD specifically for weight loss. But, if they are interested, I do advise them on how to implement it and its myriad of potential benefits.

Back to Basics

Ketogenic eating is the consumption of a diet that results in the formation of ketones. It is not “you’re in it” or “you’re out of it” (sorry all-or-nothing sapiens); it is a spectrum. More ketones will be produced by any diet lower in carbs than our standard, government-recommended, American-Diabetic-Association-endorsed culinary lunacy. After a 24-hour fast, ketones are commonly 0.5 mmol (millimolar), and many authorities consider this “in ketosis.” A range of one to three mmol is mild-to-moderate ketosis. Fasting is the quickest way to elevate ketones. What we call fasting was starving for the Ancients, our fore-people from the beginning of the Paleolithic era. With both scenarios, ketones are produced. It passes the DIMADS (Does It Make Any Darn Sense) Test that ketones, therefore, do not represent a toxic byproduct; instead, they possess many useful biochemical properties that assisted our transition from the food chains’ midsection to its apex.

The ketogenic and paleo diets are closely related. In fact, being in ketosis was a very natural part of our Paleolithic history. Both diets drastically reduce carbohydrates. Relatively low carb eating is about 130 grams of carb per day or less. Significant ketone generation, however, requires less than 50 grams per day.

Ketone Benefits

  • Improved insulin sensitivity
  • Muscle sparing (helps prevent the breakdown of our skeletal muscle)
  • Effects on gene expression (epigenetics)
  • Upregulated internal antioxidant mechanisms, thus improving cellular defense
  • Inhibited inflammatory pathways
  • Inhibited gluconeogenesis (our bodies’ production of sugar)
  • Efficient metabolic fuel
  • Increased efficiency and quantity of our mitochondria (our cellular energy factories)
  • Reduced appetite
  • Weight loss

What’s a ketone anyway?

The metabolism or burning of fats is called beta-oxidation. As a result, acetoacetate and beta-hydroxybutyrate (BHB) are formed. These are our friendly ketones—cute little fellas, much-maligned and misunderstood. (Kinda like me.)

Burgeoning research suggests that ketones, especially BHB, helps to:

  • Reduce oxidative stress and inflammation
  • Improve the pandemic of insulin resistance
  • Epigenetic effects on our gene expression

Our huge brains primarily burn glucose. However, that doesn’t mean we need to eat glucose. We make glucose from other macronutrients in a process called gluconeogenesis. Our jumbo Central Processing Units can also burn ketones. Many patients, once keto-adapted, report to me that their brain fog is gone. Headaches, lack of sleep, mood, and other brain-induced problems also commonly improve.

How to follow the ketogenic diet

Like all matters involving human eating, there is confusion and misinformation about the KD. Most people immediately picture bacon. I don’t blame them; I think about bacon a lot, too. In reality, the KD is not a diet at all but rather a framework based on relative daily caloric percentiles of macronutrients. This means roughly 70% of daily calories should come from fat, 20% from protein, and less than 10% from carbs. You might think,  “Ugh, math.” No, it’s simple really. Eat lots of fat from varied sources, and eat some protein. Avoid potato, the Big 4 grains (wheat, corn, rice, and oat), and all forms of sugar. BAM, you’re doing it! Some simplify the carby food to avoid as GPS (grain, potato, and sugar).

People who avoid ALL of the common carb sources listed above are most likely eating less than 50 grams of carb per day. It’s an important place to be if your goal is to produce ketones. Being in this sub-50 club is considered very low carb and may not be sustainable for most endurance athletes. Eating “good carbs” that put you in the low carb range of 50-150 grams per day is a good longterm strategy. Many find this to be the sweet spot for athletic performance, palatability, and sustainability. Ketones will still be made in these carb ranges, especially if you’re supplementing fat and ketones.

Coming soon on the Hammer blog and in the next issue of Endurance News:

  • How to Eat Modified Keto while doing 10+ hrs/wk of Endurance Training
  • What to Eat When You Want to go Low Carb

The KD, being more of a system than a diet, can be tailored to fit any eating pattern. The popular Mediterranean diet can be a KD. So can a plant-based, vegetarian diet. What about the Standard American Diet (SAD)? Sorry, not that one—no hope for that one!

Why people lose weight on the keto diet

You may be thinking, “But isn’t fat extremely calorically dense? Won’t it go right to my hips?” Actually, weight gain has little to do with calories. Calories from carb spike insulin and calories from fat do not. Eating a low carb, higher fat diet eliminates the postprandial (after eating) blood sugar excursions that drive cravings and hunger. Also, carbs suppress our hunger hormone ghrelin the least. So when carbs are a staple, ghrelin levels quickly spike again after a meal, which drives hunger. Functionally, this mechanism makes sense and has served humans well through history. If we found berries, figs, or a grove of starchy cattail roots, we were hormonally triggered to EAT MORE. (That means we would fight baboons and short-faced bears, search and forage, or open the fridge over and over—whatever it takes to find more.) Over time, with carb restriction and enhanced fat consumption, your total caloric intake is naturally self-restricted, especially if mindfulness with food is practiced. (A future article on that is coming, but it’s more than just what you’re eating; it’s how and when you’re eating.) So even though a ketogenic diet is energetically dense, it’s not at all unusual to consume FEWER overall calories in a day.

If you’re already comfortable with the concepts that fat does not make us fat and fat does not clog our arteries, then congratulations. You are in rarefied air. If you’re struggling with those ideas, then get some crackers and engineered low-fat cheese spread, find a comfortable chair, and read some of my past articles. Basically, any whole fat is good—tallow, lard, marrow, etc. Other excellent minimally processed fat sources include full-fat dairy (not milk) and oils (avocado, coconut, and olive). Find food that is organic, grass-fed, wild-caught, and free-running—insist on eating animals that ate their native food.

Many healthy foods contain carbs, including vegetables, nuts and seeds, fruit, dairy, and even meat. These amounts of carbs are negligible. Fruit intake should be fairly low. Aim for one to two servings per day that are chewed (not blended, mashed, or juiced) and eaten with fat sources. Vegetables vary in how starchy they are (glycemic index). Focus on less starchy ones, but beets, radishes, carrots, and yams CAN be part of a well-constructed KD.

Gradually reduce carbs and increase fat

As mentioned, the fastest way to generate ketones is to simply not eat. If you’re a carb eater, all I can say is good luck. Plummeting insulin levels result in a diuretic effect, so you’ll be going like a racehorse. Also, our meager carb stores in the form of glycogen are linked with considerable water. As we burn up our glycogen (which is important to allow burning and ketone liberation), water is liberated. Oh, and you’ll experience backaches, trouble sleeping, headaches, and just overall want to kill me. Can you imagine our fore-people feeling this way? They would have had to hunt, travel, procreate, build, flee, and fight while feeling like they had been hit by a mastodon. (It passes my DIMADS Test that treating carb as a staple instead of an occasional survival food is an unnatural event.) There is a latency in the transition from sugar burning to fat burning and ketone formation that results in several unpleasant symptoms. Remember, humans are effortless FAT STORERS. This is where the primitive brain wants to be today—silly, old-fashioned brain.

When carb is kept in its rightful place as a garnish, our bodies slowly and reluctantly transition to being FAT BURNERS, which is much healthier. To celebrate my own diet, I wear a tight-fitting half shirt that says, “I burn fat good.” (My 16-year-old hates it, but my 6-year-old wants a matching one.) Anyway, the uncomfortable transition can be ameliorated by a few weeks of gradual carb reduction and fat increase. Adding fat with medium-chain triglycerides (MCT) and using supplemental ketone salts (like KetoCaNa) help reduce symptoms by expediting ketone formation. Another method to expedite the process is the modern equivalent of starving—fasting. Just in the last few years, intermittent fasting (IF) has become mainstream. There is no shortage of podcasts, YouTube posts, and books on the subject, and there are many different methods and protocols. Here’s a little secret, it’s super easy.

The symptoms related to the non-adapted ketotic state has been termed the “Keto Flu.” Again, reducing carbs gradually as fat consumption is ramped up can prevent this. The correct amount of dietary sodium helps, too. Eating a low carb, high-fat diet without many processed foods is a very low sodium diet. For many people, 3-5 grams of sodium per day appears to be a good amount. Research has found that 5g of sodium per day was associated with the lowest risk of death from any cause.5 However, if you eat the SAD or are transitioning from the SAD, you will be REDUCING your sodium intake from the average of 10-15 grams a day.

If you are using a lot of “Keto” branded shakes, bars, and the like, be very mindful of checking for sodium content in these types of products.

It’s okay to be hungry

As part of misguided modern dietary advice, we have been programmed to eat regularly and avoid hunger. Conventional wisdom has told us to limit our portions but to eat regular meals, especially breakfast. I suggest that being hungry is a good thing and a very natural human=animal experience. Our mind and distorted physiology keep us from realizing our full potential as Great Starvers. Oh, and what about eating breakfast every day? It’s not as essential as you’ve been lead to believe. In the morning you’re just starting to burn a little fat, so keep it going! This is the underpinning of fatty coffee. No insulin spike, feel good, fat burning continues. Even beyond skipping breakfast, hunger can be good. Back before more rigorous Institutional Review Boards, Dr. Cahill at Harvard performed human studies involving subjects not eating for 40 days! (I’m told it rained the entire time.) Our modern understanding of hunger and eating patterns don’t align with how our bodies operate and how the Ancients lived.

It takes 2-7 days to generate relatively high amounts of ketones, thus entering “ketosis.” It’s not magic; all people are capable of this as it’s a deeply natural human state. But it does not mean that you are “keto-adapted.” It takes weeks for the multi-organ adaptation in which the body fully learns how to effectively use ketones. It starts quickly, but it takes the body weeks and months to fully adjust. This is not a quick fix—it’s a long-term lifestyle change. One carby meal can rapidly spin the dial back to fat storage.


Don’t get carried away with the technicalities of the KD or any diet. Any relatively low carb, higher fat way of eating results in lower insulin levels and some ketone generation. But to form higher levels of ketones, your diet choices will need to be more nuanced. I think these higher ketone concentrations do confer health benefits. What isn’t clear to me is the validity of being in ketosis all the time.

It makes sense to me that evolutionarily we normally transitioned to and from higher and lower ketone levels. Herding the now-extinct North American Camel into a pit trap likely resulted in camel meat gorging—no ketones at that feast. A favorable late summery berry forage resulted in high insulin levels and fat formation, which is the antitheses of ketones. The convoluted point I’m making is that intermittently increasing ketone levels is fine.

To help avoid the Keto Flu (and the suggestion to use breath mints by basically everyone you share air with), make sure you drink plenty of water and consume ample salt, vegetables, and fiber.

There is nothing fad about an ancient physiological state. There’s nothing trendy about possessing the cellular machinery to generate an alternative brain fuel, replete with other beneficial metabolic effects. I hope this cleared up any keto-confusion. I need to stop writing now, I haven’t eaten in 5 days and have enough ketones as it is.


Our ancients developed a more regular staple with crops and sustainable, available carbs. So I’m confused by highlighting only one section of ancestry and it’s diet fluctuations.

I’m not a sceptic per se but struggle to see where in the 90gram of carbs and hour need when riding for 4-5 hours or more that I’m going transition my body and fuel intake to cope with that;after-all, out ancestor’s didn’t find the need for that kind of sustained exercise level (long hunts maybe excepted).
Hammer Nutrition replied:
Hi Stephen, Thank you for your comments. I guess now both of us are confused – There was no selective highlighting from my reading of this article – the move from nomadic hunter gatherers to less nomadic hunter farmers was pretty much a universal thing and allowed for increased carbohydrate intake in the human population. Next, I cannot follow you apparent accepted truth that as endurance athletes we need to consume 90 grams (360 calories!) of carbs per hour. 30 to 50 grams (150-200) is closer to what can be assimilated by most athletes. Based on actual research, it’s been stated by scholarly institutions that the human liver can convert a maximum of 1 gram of carbohydrate into glycogen per minute, giving us a theoretical maximum hourly total caloric intake of 240 calories (No, the liver cannot be “trained” to perform this conversion more quickly). In my 35 years of working with athletes, 280 pound clydesdales excepted, I have not seen an athlete who could comfortably consume this many calories for more than a couple of hours without getting sick. More over, I don’t want to consume any more calories while exercising than I must to avoid slowing down. IF we set our body up to be burning fat (starting exercise in a fasted state) optimally, somewhere between 2/3 and 3/4 of the calories metabolized will come from fat, leaving only 1/4 to 1/3 of our calories expended needing to come from stored and synthesized glycogen. Starting with 2K or so stored glycogen calories and then steadily bringing in 150-180 from the onset of exercise covers our needs quite nicely and tends to produce the most bang for the buck, performance wise. BDF


Looking forward to next article as well. Thank you!!!!

Sonia Schuemann

Great article!
Please elaborate on “I have never recommended that patients eat a KD”.
I’m looking forward to:
How to Eat Modified Keto while doing 10+ hrs/wk of Endurance Training
And if it concerns athletes—What to Eat When You Want to go Low Carb


Thank you for this! I’m eagerly looking forward to your future articles on this (and other) subject.


Nicely done. Thank you!!

Megan Jackson

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